The Effect of Preform Structure on the Tensile Behaviour of Carbon/Epoxy Comosites

الملخص

Three different materials: ends, preforms, and composites were studied to determine the effect of preform structure on the fracture behaviour of the composite materials. The ends are different in their tensile characteristics while the preforms are different in their structures. The preform structures are unidirectionally laid ends (UD), a non-woven (NW), and a warp-knitted (WK) fabrics. The tensile performance and characteristics were measured at different stages; single ends, preforms, and composite materials. Different fracture behaviours were noticed for each structure. Sudden fibre fracture and epoxy cracking occurred in UD composites, whereas a gradual fracture was noticed for the NW and WK composites. For the UD composite, the fracture occurred parallel and perpendicularly to the loading direction at different positions with fibre/matrix interfacial fracture. The NW fractured in the same mode but in the middle of the specimen. The WK material showed a fracture that is perpendicular to the loading direction and the process showed a brittle fracture.